Visit our Expo - Redox and Inflammation signaling 2012

Session XVII : Cell signaling in health and disease Poster XVII, 50
Proteomic identification of cellular targets for posttranslational modification by antiinflammatory
cyclopentenone prostaglandins
Konstantinos Stamatakis, Javier Gayarre, Francisco J. Sánchez-Gómez and Dolores
Pérez-Sala
Departamento de Estructura y Función de Proteínas. Centro de Investigaciones
Biológicas, C.S.I.C., 28040 Madrid, Spain. Email: kostas@cib.csic.es
Prostaglandins with cyclopentenone structure have been shown to display protective effects in
numerous cellular and animal models of inflammation and injury. These effects have been
related to their ability to block the inflammatory response and to elicit a cellular heat shock
response. An important determinant in the beneficial effects of cyclopentenone PG is their
ability to form covalent adducts with thiol groups in proteins by Michael addition. Here we
have explored the ability of biotinylated analogs of the cyclopentenone PG, 15d-PGJ2 and
PGA1, to mimic the effect of their parent PG. Biotinylated 15d-PGJ2 inhibited the response
of renal mesangial cells to proinflammatory stimuli and elicited a cellular stress response. In
addition, both biotinylated analogs induced the activation of MAPK in murine fibroblasts.
Therefore, we have used these biotinylated PG to identify, through a proteomic approach,
some of the protein targets the modification of which may be involved in the biological
effects of cyclopentenone PG. Extracts from cells incubated in the presence of biotinylated
PG were analyzed by 2D electrophoresis and the spots showing positive biotin staining were
analyzed by tryptic digestion and MALDI-TOF mass spectrometry. In biotinylated 15d-PGJ2treated
cells we have identified several proteins involved in the regulation of cellular
architecture and dynamics, such as actin, tubulin, vimentin and tropomyosin. Modification of
vimentin was associated with a collapse of the intermediate filament network in mesangial
cells, which was reminiscent of a heat shock response. In addition, several proteins known to
be regulated by oxidative stress are also targets for the addition of 15d-PGJ2, including
Hsp90, nucleoside diphosphate kinase and methyl thioadenosine phosphorylase. The
structural and functional implications of the modification of these various targets and their
potential involvement in the biological effects of cyclopentenone PG will contribute to a
better understanding of the selectivity and therapeutic potential of these prostanoids.
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